ORIGINAL PAPER

Race, ethnicity, and the duration of untreated psychosis:a systematic review

Kelly K. Anderson • Nina Flora • Suzanne Archie •

Craig Morgan • Kwame McKenzie

Received: 1 February 2013 / Accepted: 23 October 2013

� Springer-Verlag Berlin Heidelberg 2013

Abstract

Purpose An extended duration of untreated psychosis

(DUP) is associated with poor outcome in first-episode

psychosis (FEP). Some have suggested that minority ethnic

groups have longer treatment delays, and this could lead to

worse outcomes. We systematically reviewed the literature

on racial and ethnic differences in DUP in patients with

FEP.

Methods We searched electronic databases and con-

ducted forward and backward tracking to identify studies

that had compared DUP for people with FEP from different

racial or ethnic groups.

Results We identified ten papers that reported on the

association between race or ethnicity and DUP. Overall,

these studies did not find evidence of differences between

groups; however, three of ten studies suggested that Black

patients generally, and Black-African patients specifically,

may have a shorter DUP relative to White patients. There

were methodological limitations in most studies with

respect to ethnicity classification, sample size, and adjust-

ment for potential confounders.

Conclusion Racial and ethnic differences in DUP were

rarely found. This could reflect that DUP does not differ

between groups, or may reflect the methodological limi-

tations of prior research. Studies that are designed and

powered to examine these differences in treatment delay

are needed to determine whether there are differences in

DUP for minority groups.

Keywords First-episode psychosis � Duration of

untreated psychosis � Ethnicity � Race � Treatment

delay � Early intervention

Background

An extended period from the onset of psychotic symptoms

to the initiation of treatment is associated with poor out-

comes in first-episode psychosis (FEP), as measured by

remission of symptoms, levels of subsequent functioning,

and quality of life [1–3]. This period has been termed the

duration of untreated psychosis (DUP), and is considered to

be a potentially modifiable predictor of prognosis in FEP

and a target for secondary prevention. A comprehensive

understanding of the factors that determine and moderate

DUP could help to inform the development of more

effective services. A review by Compton and Broussard [4]

discusses the myriad of factors that may operate at different

levels to influence DUP, and they classify these factors as

demographic, pre-morbid and onset-related, illness-related,

family-level, societal, and health services/system-level

factors. The evidence base for many of the potential

determinants of DUP is scant or inconclusive.

K. K. Anderson (&) � N. Flora � K. McKenzie

Social and Epidemiological Research, Centre for Addiction and

Mental Health (CAMH), 455 Spadina Avenue, Suite 300,

Toronto, ON M5S 2G8, Canada

e-mail: kelly.anderson@camh.ca

S. Archie

Department of Psychiatry and Behavioural Neurosciences,

McMaster University, 25 Charlton Avenue East, Suite 703,

Hamilton, ON L8N 1Y2, Canada

C. Morgan

Section of Social Psychiatry, Institute of Psychiatry, King’s

College London, De Crespigny Park, London SE5 8AF, UK

K. McKenzie

Department of Psychiatry, University of Toronto, 455 Spadina

Avenue, Suite 300, Toronto, ON M5S 2G8, Canada

123

Soc Psychiatry Psychiatr Epidemiol

DOI 10.1007/s00127-013-0786-8

The race and ethnicity of a person are examples of

demographic factors that have the potential to impact the

DUP. There is a considerable literature on the utility of

race and ethnicity as concepts [5, 6]. Race typically refers

to physical features, such as skin color or hair texture,

which may reflect a person’s ancestry, and examples of

categories that are commonly used to describe race include

White, Black, or Asian. Ethnicity is a complex term used to

describe perceived social groupings based on a sense of

belonging, place of origin, and other factors such as lan-

guage, religion, and sometimes race [7]. For example,

descriptors that might be used to classify ethnicity include

Black-Caribbean, Black-African, White-European, or

White-Canadian. Both racial and ethnic categorizations

have been used in comparative research between minority

and majority groups. Racial and ethnic groupings are not

mutually exclusive, and in the social world they may map

onto each other. They both may have an impact on DUP

because as variables they capture shared socio-cultural

factors that have an effect on access to care. However,

because they are different concepts there may be differ-

ences in the mechanism through which they are associated

with DUP. Because of this, we have investigated both

categories and we will distinguish between the concepts

where it is important and relevant to do so.

Numerous barriers to mental health care have been

reported for different ethnic and racial groups, and the

reasons for these are numerous and varied. Different

groups may hold different beliefs about the cause of psy-

chotic symptoms, their perceived severity, and the most

appropriate course of action [8, 9]. Language barriers or a

lack of information regarding the availability of services

and how to access them may influence an individual’s

decision to seek help [10]. There may be differences in the

degree or type of stigma in different communities [11].

Finally, there may be differences in the accessibility of

services to different groups because of the cost, the loca-

tion of services, the use of models that are not considered

appropriate by some groups, or the perception that services

are not culturally competent or trustworthy [12].

As a result of these barriers to care, some groups may

take alternative routes to accessing services, and differ-

ences in pathways to care for psychotic disorders have been

documented between groups [13]. The majority of prior

research in this area has focused on people of African or

Caribbean origin in high-income countries, and has

reported that these groups were more likely than the

majority ethnic group to access care through involuntary

hospitalizations and the criminal justice system, and less

likely to have general practitioner (GP) involvement on the

pathway to care [14].

Both barriers to care and differences in pathways to care

could lead to differences in DUP. It is often assumed that

these barriers to care result in minority groups with FEP

having a longer DUP [15]. However, given the multi-fac-

eted nature of the pathways to care [16], it is not imme-

diately clear what the impact of race or ethnicity will be.

There is currently no consensus on whether or how race

and ethnicity have an impact on DUP. Despite the large

body of research on various factors associated with DUP

[4], there has been no systematic review or meta-analysis

of the social determinants of DUP, with the exception of

gender [17].

The aim of this study was to systematically review the

literature on ethnic and racial differences in DUP among

patients with first-episode psychosis. Because DUP is

affected by the availability and accessibility of services

within a given health system, and there are differences in

service provision between low-, middle-, and high-income

countries, we restricted this review to research conducted

in high-income countries to help ensure comparability

across the studies.

Methods

Systematic review

We conducted an electronic search of the MEDLINE

(1950–2012), HealthStar (1966–2012), EMBASE

(1980–2012), and PsycINFO (1967–2012) databases using

the OvidSP platform, and we also searched Web of

Knowledge. The MEDLINE and HealthStar search terms

are presented in ‘‘Appendix’’, and this strategy was adapted

for EMBASE and PsycINFO using analogous terms rele-

vant to these databases. The Web of Knowledge was

searched using key words. The search strategy was devel-

oped in consultation with a librarian.

We obtained further studies by manually searching

personal files and the bibliographies of all relevant studies

and review articles. We performed forward citation

searching using Web of Knowledge to locate all articles

that had cited the included studies. When abstracts or

unpublished studies were retrieved in our search, we con-

tacted the corresponding authors to determine whether the

work had subsequently been published in a peer-reviewed

journal. We regularly updated all segments of the literature

search, with the final update in September 2012.

Each study was reviewed for the following inclusion

criteria: (a) the study measured DUP among individuals

with FEP; (b) the article reported DUP by race or ethnic

group, or used race or ethnicity as a covariate in the

analyses; (c) the study was conducted in a high-income

country [18]; (d) the findings were published in a peer-

reviewed journal. We did not impose any restrictions with

respect to date or language of publication.

Soc Psychiatry Psychiatr Epidemiol

123

For all included papers, two independent reviewers

extracted data on key elements of study design, the defi-

nition and measurement of DUP, the methods used for

assigning race or ethnicity, and measures of the central

tendency and dispersion of DUP by racial or ethnic group.

All papers were assigned a quality assessment score using a

rating scale based on a tool used in previously published

systematic reviews on ethnic differences in pathways to

care (Table 1) [13, 19]. Discrepancies between the

reviewers were resolved by consensus. Where important

methodological details were missing from the paper, such

as the definition of DUP or the methods used for assigning

race or ethnicity, we consulted other studies from the same

research group and patient sample, where available, to

obtain the missing information. However, the quality

assessment ratings were done solely based on information

contained within the included paper. Authors were con-

tacted for further information or clarification when the data

were aggregated or unclear.

Meta-analysis

For all studies identified in the systematic review, we

contacted the corresponding author to obtain log-trans-

formed means and standard deviations for DUP. These

were needed due to the positively skewed distribution of

DUP, and studies were excluded from the meta-analysis if

the authors were unable to provide these data.

For all studies for which we had log-transformed data,

we calculated the standardized mean difference (SMD)

with 95 % confidence intervals (CI) using Cohen’s d for

each racial or ethnic subgroup, relative to the majority

racial or ethnic group. We meta-analyzed these effect

estimates using the metan procedure in Stata 11.0. There

was an insufficient number of papers to compare most of

the racial or ethnic variables. Therefore, we restricted the

analysis to data comparing the two groups most commonly

investigated, specifically a Black grouping, made up of

African or Caribbean origin populations, and an Asian

grouping. These were compared to a White grouping rep-

resenting the majority racial group. One of the studies

presented data separately for Black-African and Black-

Caribbean patients [15], and another divided the samples

by first-generation Black-African and Black-Caribbean

groups and second-generation Black-British groups [20];

therefore, we pooled these estimates by calculating

weighted means and standard deviations to allow compa-

rability with other studies. Two studies also divided the

White sample by native-born individuals and immigrants

[20, 21], and these groups were also pooled for the meta-

analysis. There were insufficient data available for a meta-

analysis of estimates for other racial groups, or for disag-

gregated racial or ethnic groups.

Statistical heterogeneity was assessed using the I2 sta-

tistic, with values of 25, 50, and 75 % suggestive of low,

moderate, and high heterogeneity, respectively [22]. There

was a high likelihood of methodological and contextual

heterogeneity due to the different definitions used for DUP,

race and ethnicity, as well as the different health service

contexts of each of the studies; therefore, we opted to use a

random effects model to compute a summary effect size

Table 1 Rating system for methodological quality (adapted from

Bhui et al. [13] and Sass et al. [19])

Legend Description

Adequacy of sample size

- No power calculation or inadequate sample to detect racial

or ethnic differences

? Authors demonstrate that the sample was powered to detect

racial or ethnic differences

Definition of the first episode of psychosis

- Not described

• Based on first hospitalization

? Based on duration of antipsychotic treatment or first

presentation to a clinical setting

Adjustment for confounding variables

- None

• Age and/or gender

? Other co-morbidities or risk factors for the outcome of

interesta (see below)

Quality of race or ethnicity measurement

- Not reported

• Third party report (e.g., staff categorization, name-based

method)

? Self-reported race or ethnicity

Use of race or ethnicity in the analysis

- Ethnic groups dichotomized (e.g., white vs. others)

• Reasonable groupings by race

? All analyses done on specific ethnic groups without

amalgamation

Definition of DUP

- Definition of DUP unclear (e.g., no description of start/end

point)

? Clear definition of DUP

Measurement of DUP

- Not described/non-systematic method used for dating DUP

? Use of a standardized measurement tool for dating DUP

Source of data on DUP

- Not described/chart review or third party report only

• Patient report only

? Patient report corroborated with chart review or third party

information

-, Criteria not met; •, Criteria partially met; ?, Criteria satisfieda Risk factors include socio-economic factors (SES, employment,

household size, marital status); Co-morbidities include drug and

alcohol use, coexisting psychiatric conditions, violence to others

Soc Psychiatry Psychiatr Epidemiol

123

[23]. The source of the heterogeneity was explored using a

meta-regression model [24]. The study characteristics that

were used as predictor variables in the model included

country of origin, as well as quality assessment ratings for

the method of defining the first episode of psychosis, the

measurement of race or ethnicity, and the tool used for

measuring and defining the DUP (Table 1).

Results

The electronic database search retrieved 527 studies, of

which 38 were potentially relevant for this review. We

identified an additional 12 papers from personal files and

the manual search, for a total of 50 full-text articles

reviewed for inclusion. We excluded 40 studies for the

following reasons (not mutually exclusive): not a FEP

population (n = 5); review article, case report, or research

letter (n = 5); DUP was not measured (n = 9); race and

ethnicity were not measured (n = 6); no comparison group

(n = 10); study was conducted in a low- or middle-income

country (n = 4); the study reported duplicate data from

samples that were already included in the review (n = 7).

As a post hoc exclusion, we removed a multi-site clinical

trial from the review [25] because the endpoint for DUP for

a large proportion of patients was entry into the clinical

trial, which is substantially different from the other studies

which measured the time to antipsychotic prescription or

first contact with services. In total, ten studies met the

inclusion criteria for our review, and the authors of seven

of these studies provided the required data for inclusion in

the meta-analysis (Fig. 1).

Study characteristics

The characteristics and findings of included studies are

summarized in Tables 2 and 3, and the quality assessment

ratings for study methodology are presented in Table 4.

The studies primarily used observational designs and were

conducted in Canada, England, New Zealand, Singapore,

or the USA. The size of the study samples varied sub-

stantially, ranging from 55 to 535 participants (median

across studies = 256). Approximately, half of the studies

(n = 5) restricted their samples to non-affective psychoses.

The first episode of psychosis was defined based on the use

of antipsychotic medication in four studies, first contact

with services in three studies, and first inpatient admission

in three studies (Table 2).

Most studies (n = 6) used a standardized instrument for

measuring DUP, and nearly all (n = 9) used multiple data

sources to corroborate information. The studies used sim-

ilar starting points for measuring DUP, specifically the

Full-text version retrieved for more detailed evaluation (n = 50)

Studies meeting the inclusion criteria (n = 10)

Unique citations screened for relevancy (n = 527)

Studies excluded (n = 489)

Studies excluded from review, with reasons (n = 40)*- Not a first-episode population (n=5)- Review article/case report/letter (n=5)- DUP not measured (n=9)- No ethnicity (n=6)- No comparison group (n=10)- Low-income country (n=4)- Clinical trial (n=1)- Duplicate data (n=7)

Forward and backward citation searching

(n = 8)

Review of personal files (n = 4)

Medline and HealthStar Search

(n = 205)

Studies excluded from meta-analysis (n = 3)- Required data not available from

authors (n=3)

Data available for meta-analysis (n = 7)

EMBASE Search

(n = 225)

PsycINFO Search

(n = 86)

Web of Knowledge Search

(n = 233)

Fig. 1 Flow chart of the search

strategy and exclusion process

for the systematic review

Soc Psychiatry Psychiatr Epidemiol

123

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Soc Psychiatry Psychiatr Epidemiol

123

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Soc Psychiatry Psychiatr Epidemiol

123

onset of positive psychotic symptoms. However, the end-

points for DUP varied across the studies, with the majority

(n = 7) using the initiation of adequate antipsychotic

treatment as the end of DUP (Table 3). One study mea-

sured two different end-points for DUP, specifically the

initiation of antipsychotic treatment and entry into early

intervention services, to assess the impact of this definition

on observed estimates [20].

Few studies (n = 5) reported how race or ethnicity was

measured, and among those who did, three used a measure

involving self-report. Only three studies performed analy-

ses on specific ethnic groups without amalgamation by race

[15, 20, 26], and two distinguished between the first- and

second-generation immigrant populations of African,

Caribbean, or European origin [20, 21]. The classifications

of race and ethnicity that were used in each of the studies

are shown in Table 3.

None of the included studies met all of our criteria for

methodological quality (Table 4). The most common

problems across the studies were as follows: not using a

self-report measure for race or ethnicity, or not describing

how it was measured (n = 8); lumping different ethnic

groups together by race (n = 7); and lack of adjustment for

potential confounding (n = 8). None of the studies dem-

onstrated that the sample size was adequate for detecting

racial or ethnic differences in DUP (Table 4).

Racial and ethnic differences in DUP

Only two studies included in our review explicitly stated

that the primary objective was to examine racial or ethnic

differences in DUP [15, 20]. The objective of the remain-

ing studies was to look at differences between groups in

symptomatology [21] or pathways to care [27], to examine

other determinants of DUP [26], to look at the association

between DUP and clinical outcomes [28, 29], or to describe

pathways to care generally [30]. The two remaining studies

did not present data on DUP for different groups, but rather

used these variables as a covariate when examining other

determinants of the DUP [31, 32]. Given that most studies

were not designed to examine racial or differences in DUP,

it is not surprising that none of the studies demonstrated

that they had achieved an adequate sample size to achieve

this objective.

Only three studies found evidence of racial or ethnic

differences in DUP. Haas and colleagues dichotomized

DUP and found that a greater proportion of Black-Ameri-

can patients had a DUP of less than 1 year, whereas a

greater proportion of Asian-American patients had a delay

of 1 year or longer. There were no differences observed for

White, Hispanic, or Other racial groups [29]. Morgan and

colleagues [15] found that patients of Black-African origin

had a significantly shorter DUP compared with both White-

British and Black-Caribbean patients. Similarly, Ghali and

colleagues [20] found that White-British patients had a

significantly longer DUP when compared with Black-

African patients, but the differences for Black-Caribbean

patients did not reach statistical significance, possibly

owing to the much smaller sample size. The second-gen-

eration immigrant Black group, and the first-generation

immigrant White group, also had a shorter DUP than the

White-British group when entry into early intervention

services was used as the endpoint, but not when the initi-

ation of antipsychotic medication was the endpoint for

DUP [20]. In contrast to Haas and colleagues, Ghali and

colleagues [20] found that patients of South Asian origin

had a shorter DUP, compared with the White-British group.

Interestingly, some of these differences in DUP between

the ethnic groups were attenuated once differences in the

pathway to care were accounted for. The remaining studies

Table 4 Quality assessment ratings for studies included in the systematic review (n = 10)

Adequacy of

sample size

Definition

of FEP

Adjustment for

confounding

Race/ethnicity

measurement

Race/ethnicity

categories

Definition

of DUP

Measurement

of DUP

DUP data

source

Archie et al. [27] - ? - ? • ? ? ?

Brunet et al. [31] - ? - - • ? ? ?

Compton et al. [32] - ? - - • ? ? ?

Drake [28] - - - - • - - ?

Ghali et al. [20] - ? ? • ? ? ? ?

Haas et al. [29] - - - - • ? - ?

Morgan et al. [15] - - ? ? ? ? ? ?

Pek et al. [26] - ? - - ? ? - ?

Turner et al. [30] - ? - - - ? - -

van der Ven et al. [21] - ? - • • - ? ?

Ratings are based solely on the information contained within the included article. See Table 1 for scoring criteria

-, Criteria not met; •, Criteria partially met; ?, Criteria satisfied

Soc Psychiatry Psychiatr Epidemiol

123

did not find a statistically significant association between

race and DUP [21, 26–28, 30–32].

Meta-analysis

Our meta-analysis computing an overall effect of Black

and Asian groups relative to White did not show evidence

of differences in DUP between these groups (Fig. 2). The

pooled SMD in DUP for Black patients was 0.01 (95 %

CI = -0.16, 0.18). The pooled SMD in DUP was 0.00

(95 % CI = -0.38, 0.37) for Asian patients. There was

evidence of moderate heterogeneity in these data (Black

I2 = 46.3 %; Asian I2 = 66.6 %), and the source of this

was explored using meta-regression techniques; however,

none of the study-level variables included in our models

was a significant source of heterogeneity (data not shown).

Discussion

Main findings

Our systematic review of the literature found little evidence

to support the belief that particular racial or ethnic groups

have a longer DUP at the first episode of psychosis, as only

three of ten studies reported differences across groups. The

relatively small number of studies that examined such

differences in DUP, as well as the methodological limita-

tions of available studies, makes it difficult to draw firm

conclusions. The three studies that did report differences

suggest that in high-income countries, Black patients

generally [29], and Black-African patients in particular [15,

20], may have shorter treatment delays relative to White

patients. The two studies that found significant differences

in DUP for Asian patients compared to White patients had

conflicting findings [20, 29].

The evidence for many of the social determinants of

DUP is scant or inconclusive [4]. The determinants of DUP

operate at many levels, including the individual and their

family, as well as the larger cultural, societal, and health

service context. Both race and ethnicity are complex con-

structs, and the interplay between the determinants of DUP

and these variables is likely to be similarly convoluted. A

person’s racial or ethnic identity may have different inter-

actions with both barriers and pathways to care. Given this,

and the possibility that the various interactions may either

increase or decrease the DUP, it may not be surprising that

most studies report no differences between groups.

With few exceptions, the studies included in our review

assessed racial differences in treatment delay, with little

consideration of ethnicity, culture, or immigration status.

The utility of race as a research variable has been ques-

tioned, in part due to the significant heterogeneity of people

within each category. The articles by Ghali, Morgan, Pek

[15, 20, 26], and their respective colleagues were the only

studies to analyze differences in DUP with no amalgama-

tion of ethnic groups into racial groups. It is noteworthy

that the two studies that disaggregated the Black group by

NOTE: Weights are from random effects analysis

.

.

Black vs. White

Archie et al.

Drake et al.

Ghali et al.

Morgan et al.

van der Ven et al.

Compton et al.

Subtotal (I-squared = 46.3%, p = 0.097)

Asian vs. White

Archie et al.

Ghali et al.

van der Ven et al.

Subtotal (I-squared = 66.6%, p = 0.050)

Study

2010

2000

2013

2006

2012

2008

2010

2013

2012

Year

Canada

England

England

England

Canada

United States

Canada

England

Canada

Country

0.23 (-0.17, 0.63)

-0.12 (-0.59, 0.35)

-0.22 (-0.40, -0.04)

0.08 (-0.12, 0.27)

-0.02 (-0.38, 0.34)

0.30 (-0.14, 0.75)

0.01 (-0.16, 0.18)

0.26 (-0.18, 0.69)

-0.32 (-0.60, -0.03)

0.14 (-0.28, 0.56)

-0.00 (-0.38, 0.37)

SMD (95% CI)

12.26

9.81

27.11

26.02

14.26

10.55

100.00

30.18

38.87

30.95

100.00

Weight

%

0.23 (-0.17, 0.63)

-0.12 (-0.59, 0.35)

-0.22 (-0.40, -0.04)

0.08 (-0.12, 0.27)

-0.02 (-0.38, 0.34)

0.30 (-0.14, 0.75)

0.01 (-0.16, 0.18)

0.26 (-0.18, 0.69)

-0.32 (-0.60, -0.03)

0.14 (-0.28, 0.56)

-0.00 (-0.38, 0.37)

SMD (95% CI)

9.81

27.11

26.02

14.26

10.55

100.00

30.18

38.87

30.95

100.00

Weight

%

Shorter DUP Longer DUP 0-1 1

Fig. 2 Meta-analysis of the log-transformed standardized mean difference (SMD) in duration of untreated psychosis for Black and Asian racial

groups relative to White

Soc Psychiatry Psychiatr Epidemiol

123

ethnicity found that patients of African origin specifically

tended to have a shorter DUP [15, 20]. Lumping African

origin and Caribbean origin groups together as Black, as

we did in the meta-analysis, may mask significant differ-

ences in DUP between these groups. A lack of dis-aggre-

gation of racial groups was common across the included

studies, which could have led to a similar cancellation of

effects. Given this, the results we present for the meta-

analysis of racial differences in DUP should be interpreted

with caution.

The tests for the meta-analysis found evidence of mod-

erate heterogeneity among the studies, which indicates that

these data arise from different populations and difficulties

may arise from pooling these samples. Additional hetero-

geneity within the groups could arise from the role that

immigration status plays. First-generation immigrants with

FEP in the Netherlands have a significantly longer DUP

than second-generation or native-born individuals [33].

This could reflect many factors such as differences in

knowledge of local availability of services, a reluctance to

seek help from mainstream services, or language barriers.

However, most studies did not report whether their groups

were immigrants and whether they were first- or second-

generation. Of exception, Ghali and colleagues did report

DUP estimates separately for first-generation White immi-

grants and White-British people, and also for first-genera-

tion African and Caribbean people and second-generation

Black-British people. Although the impact of immigration

status was not formally tested, there does appear to be a

trend for the second-generation of both groups to have a

longer DUP than the first-generation immigrants [20],

which is in contrast to the findings from the Netherlands

[33]. Additional studies are needed to elucidate the role of

immigration status on treatment delay in FEP.

A further limitation to the studies included in our review

is that all studies, with the exception of two [15, 20], used

simple univariate analyses to examine the association

between racial or ethnic groups and DUP, and did not

adjust the effect estimates for potential confounding fac-

tors. Although much of the prior literature on the deter-

minants of treatment delay have been inconclusive, several

factors are consistently found to be associated with DUP,

including age of onset, premorbid functioning, mode of

onset of psychosis, negative symptoms, social functioning,

insight, and a diagnosis of non-affective psychosis [4].

Indicators of the pathway to care have also been shown to

be associated with treatment delay [20, 34]. If these factors

are also associated with a person’s racial or ethnic back-

ground, a failure to adjust for their confounding effects

using multivariate models will obscure the true association

between race or ethnicity and DUP. There is some evi-

dence to suggest that there may be racial and ethnic dif-

ferences in the clinical presentation of first-episode

psychosis [21, 35] and the pathway to care [14], as well as

differences in social factors [36, 37], suggesting that a

rigorous analysis of the association between race or eth-

nicity and DUP should account for these and other poten-

tially confounding variables.

The limited sample size of most included studies, the

problems with group definition, and the heterogeneity of the

samples are key limitations in the available literature.

However, there also needs to be some attention given to how

DUP is defined and operationalized. Ghali and colleagues

[20] reported differences in the observed association

between ethnicity and DUP when admission to early inter-

vention services was used as the endpoint of DUP, rather

than the initiation of antipsychotic medication. Additionally,

delay in treatment has been conceptualized by others as

consisting of two phases; a help-seeking phase, which is the

period between symptom onset and first contact with health

services, and a referral phase, which consists of the time

between first contact and referral to an appropriate treatment

program for first-episode psychosis [31, 38, 39]. There may

be independent associations between group membership and

each of these phases. For instance, patients of African and

Caribbean origin are more likely to come into contact with

police and emergency services on their pathways to care

[14]. These groups may be reluctant to seek help initially and

have a longer help-seeking delay, but then subsequently

have a relatively short referral delay as a consequence of

their contact with emergency services. As a result, they

would appear to have a similar overall DUP to comparison

groups, but the sub-components that comprise the DUP are

of different lengths. The findings from a previous study by

Harrison and colleagues support this [40], although this

study did not meet inclusion criteria for our review. The

investigators found no difference in the duration of untreated

illness between Black-Caribbean patients and the general

population, but did find that contact with services came later

for Black-Caribbean patients. However, once contact was

made, Black-Caribbean patients received psychiatric care

sooner than the general population [40].

It has also been suggested that White patients may be

more likely to be seen earlier in primary care, which may

delay contact with secondary services [15]. Indeed, prior

research suggests that individuals who are in contact with

primary care services have longer delays between first

contact and contact with specialized services [20, 34, 41],

whereas those who are in contact with emergency services

have shorter delays [20, 41]. Consequently, differences in

the propensity to utilize primary care or emergency ser-

vices may distort cross-group comparisons of the overall

DUP. A more detailed assessment of the determinants of

different components of DUP may be more informative for

determining whether differences exist and the potential

mechanisms behind such differences. This level of detail

Soc Psychiatry Psychiatr Epidemiol

123

may be required to inform the development of interven-

tions aimed at reducing treatment delay.

Limitations

Our findings should be interpreted in light of a number of

limitations. We were only able to identify ten studies that

reported data on race or ethnicity and DUP, despite the

large number of studies to date that have reported DUP

estimates or examined its determinants [1–4]. This raises

the question of publication bias, as studies may have

examined the association between DUP and race or eth-

nicity and failed to report negative findings. Additionally,

we were unable to obtain log-transformed data from three

of the studies, so the meta-analysis does not include the

totality of evidence on ethnic differences in DUP.

The quality assessment tool that we employed has not

been previously validated. The studies included in our

review used various tools to measure DUP, and the cross

cultural validity of these measures has not been previously

assessed. The included studies also did not typically report

estimates of reliability, which is necessary to ensure there

are not systematic differences in estimating the DUP across

groups [15]. Furthermore, the included studies varied with

respect to the way that DUP was operationalized, which is

a common problem across studies reporting DUP [42], and

the use of different start- or end-points for DUP could have

an impact on observed trends. The conclusions drawn from

these data should be interpreted in light of this heteroge-

neity in the outcome measure.

Research implications

In spite of these limitations to our review, we are able to

conclude that prior research on racial and ethnic differ-

ences in DUP has substantial methodological limitations.

Studies that are designed and powered to examine differ-

ences in treatment delay are needed to further our under-

standing of the challenges faced by patients with psychosis

when seeking help for a first-episode. Additionally, our

review highlights the need for consistent and routine data

collection across early intervention services to allow

comparability across different programs and health service

contexts. This would include the measurement of ethnicity

with minimal aggregation by racial group, as well as the

use of standardized and validated measurement tools for

DUP and pathways to care. However, the challenges

associated with establishing such a consensus are sub-

stantial, and have been discussed elsewhere in the literature

[5, 42–44].

Knowledge of the impact of both race and ethnicity on

treatment delay is crucial for the field of early psychosis for

a number of reasons. Firstly, the association between DUP

and adverse clinical and functional outcomes is well

known, and racial and ethnic differences in outcomes for

psychosis have also been previously documented, although

inconsistently across the literature [45]. If race or ethnicity

is related to DUP, then there are important implications for

its role as a confounding factor in the observed association

between DUP and outcome. Secondly, information on the

impact of race, ethnicity, and other determinants is crucial

for informing the development of interventions aimed at

reducing DUP and improving outcomes. Finally, as high-

income countries become more culturally varied and eth-

nically diverse, information on racial and ethnic differ-

ences in treatment delay is imperative to inform the

provision of culturally appropriate and equitable mental

health services.

Acknowledgments We are grateful to the authors of the included

studies who generously shared data and information to aid in the

completion of this review. We also appreciate the guidance provided

by the Biostatistics Consulting Unit at the Centre for Addiction and

Mental Health (CAMH). This study was funded by a Canadian

Institutes of Health Research (CIHR) Operating Grant (Grant

#220976). Kelly Anderson is supported by a Postdoctoral Fellowship

Award from CIHR. Craig Morgan is supported by funding from the

Medical Research Council (Ref: G0500817), Wellcome Trust (Grant

Number WT087417), and European Union (European Community’s

Seventh Framework Program (Grant Agreement No. HEALTH-F2-

2009-241909) (Project EU-GEI). The authors have no conflicts of

interest with respect to the publication of this manuscript.

Appendix: Terms used for Medline search strategy

[exp. Schizophrenia and Disorders with Psychotic Fea-

tures/OR

exp. Affective Disorders, Psychotic/OR

psychosis.mp OR

psychotic disorder$.mp OR

schizophreni$.mp OR

severe mental illness$.mp]

AND

[exp. Population Groups/OR

ethnic$.mp OR

visible minorit$.mp OR

ethno$.mp OR

immigra$.mp OR

migration.mp OR

afro$.mp OR

africa$.mp OR

caribbean.mp OR

black.mp OR

europ$.mp OR

white.mp]

AND

[exp. Time Factors/OR

duration of untreated psychosis.mp OR

Soc Psychiatry Psychiatr Epidemiol

123

duration of untreated illness.mp OR

DUP.mp OR

DUI.mp OR

treatment delay.mp OR

referral delay.mp OR

help-seeking delay.mp OR

early intervention.mp]

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